Transcervical fallopian tube occlusion devices and their delivery

ABSTRACT

The invention provides intrafallopian devices and non-surgical methods for their placement to prevent conception. The efficacy of the device is enhanced by forming the structure at least in part from copper or a copper alloy. The device is anchored within the fallopian tube by imposing a secondary shape on a resilient structure, the secondary shape having a larger cross-section than the fallopian tube. The resilient structure is restrained in a straight configuration and transcervically inserted within the fallopian tube, where it is released. The resilient structure is then restrained by the walls of the fallopian tube, imposing anchoring forces as it tries to resume the secondary shape.

CROSS-REFERENCES TO RELATED APPLICATIONS

[0001] This application is a continuation of, and claims the benefit ofpriority from U.S. patent application Ser. No. 09/591,874 (AttorneyDocket No. 016355-002420US), filed Jun. 12, 2000, which is acontinuation of, and claims the benefit of priority from U.S. patentapplication Ser. No. 08/474,779 (Attorney Docket No. 016355-002400US),filed Jun. 7, 1995, the full disclosures of which are incorporatedherein by reference.

STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSOREDRESEARCH OR DEVELOPMENT

[0002] NOT APPLICABLE

REFERENCE TO A “SEQUENCE LISTING,” A TABLE, OR A COMPUTER PROGRAMLISTING APPENDIX SUBMITTED ON A COMPACT DISK.

[0003] NOT APPLICABLE

BACKGROUND OF THE INVENTION

[0004] 1. Field of the Invention

[0005] The present invention relates generally to contraception, andmore particularly to intrafallopian contraceptive devices andnonsurgical methods for their delivery.

[0006] Worldwide demand exists for safe, effective methods of bothcontraception and permanent sterilization. Although a variety ofcontraception and sterilization methods are available, all of theexisting methods have limitations and disadvantages. Thus, the need foradditional safe, low cost, reliable methods of contraception andpermanent sterilization, both in developed and less developed countries,is widely recognized.

[0007] Many presently available contraception methods requiresignificant user involvement, and user non-compliance results in quitehigh rates of failure. While the theoretical effectiveness of existingcontraceptives, including barrier methods and hormonal therapies, iswell established, overcoming user noncompliance to improve overallefficacy has proven difficult.

[0008] One form of contraception which is less susceptible to usernoncompliance is the intrauterine device (IUD). IUDs have been found tohave higher rates of reliability, and are effective for a longer periodof time, than most other commercially available contraceptives.Unfortunately, IUDs are also associated with serious infectiouscomplications. For this reason, the use of IUDs within the United Stateshas decreased dramatically. Additionally, IUDs are subject to unplannedexpulsion, and must be removed due to excessive pain or bleeding in apercentage of cases, further reducing the acceptance of the IUD as acontraceptive method. Interestingly, the efficacy of copper IUDs appearsto be higher than that of non-metallic IUDs. The reason for this has notbeen fully explained.

[0009] Commercially available options for permanent sterilizationinclude fallopian tube ligation and vasectomy. These methods aresurgical, are difficult to reverse, and are not available to many peoplein the world. It is common knowledge that fertilization occurs in thefallopian tubes where the sperm and ovum meet. Tubal ligation avoidsthis by complete occlusion of the fallopian tubes.

[0010] It has previously been proposed to reversibly occlude thefallopian tubes, for example, by in vitro formation of an elastomericplug, or otherwise anchoring a device on either side of the narrowestregion of fallopian tube, called the “isthmus.” Such fallopian tubeocclusion methods appear promising; however, an unacceptably highpercentage of the non-surgical devices proposed to date have becomedislodged during previous studies. Even where non-surgicalintrafallopian devices have remained in place, they have been found tobe only moderately effective at preventing conception.

[0011] For these reasons, it would be desirable to provide effective,reliable intrafallopian devices for contraception and sterilization. Itwould be particularly desirable to provide highly effectiveintrafallopian devices which did not require surgery for placement. Itwould be especially desirable if such devices and methods allowed easyplacement of the device, but were less susceptible to being dislodgedthan previously proposed non-surgical intrafallopian devices.

[0012] 2. Description of the Related Art

[0013] The experimental use of a stainless steel intrafallopian deviceis described in Transcatheter Tubal Sterilization in Rabbits, Penny L.Ross, RT 29 “Investigative Radiology”, pp. 570-573 (1994). Theexperimental use of an electrolytically pure copper wire as a surgicalcontraceptive intrafallopian device in rats was described in“Antifertility Effect of an Intrafallopian Tubal Copper Device”, D. N.Gupta, 14 Indian Journal of Experimental Biology, pp. 316-319 (May1976).

[0014] U.K. Patent Application Pub. No. 2,211,095 describes a uterinescrew plug for blocking the fallopian tube. European Patent ApplicationPub. No. 0,010,812 describes a device for placement in the oviductshaving enlargements at either end for anchoring the device. The samedevice appears to be described in Netherlands Patent No. 7,810,696.

[0015] The use of tubal occlusion devices is described in “HysteroscopicOviduct Blocking With Formed-in-Place Silicone Rubber Plugs”, Robert A.Erb, Ph.D., et al., The Journal of Reproductive Medicine, pp. 65-68(August 1979). A formed-in-place elastomeric tubal occlusion device isdescribed in U.S. Pat. No. 3,805,767, issued to Erb. U.S. Pat. No.5,065,751, issued to Wolf, describes a method and apparatus forreversibly occluding a biological tube. U.S. Pat. No. 4,612,924, issuedto Cimber, describes an intrauterine contraceptive device which sealsthe mouths of the fallopian tubes.

[0016] German Patent No. 28 03 685, issued to Brundin, describes adevice for plugging a body duct with a device which swells when incontact with a body fluid.

[0017] Alternative contraceptive devices are disclosed in copending U.S.patent application Ser. No. 08/475,252, filed Jun. 7, 1995, the fulldisclosure of which is herein incorporated by reference.

SUMMARY OF THE INVENTION

[0018] The present invention provides intrafallopian devices and methodsfor their placement to prevent conception. The intrafallopian devices ofthe present invention are transcervically delivered, resilientlyanchored structures which are formed at least in part from copper toprovide long term contraception, or alternatively permanentsterilization, without the need for surgical procedures or the increasedbleeding, pain, and risks of infection associated with intrauterinedevices (IUDs).

[0019] The use of copper in the intrafallopian device of the presentinvention improves its efficacy as a contraceptive method. Devicesformed from plastically deformable materials, however, are less readilyrestrained in the fallopian tube. Apparently, the large variation in theactual shape and dimensions of fallopian tubes does not provide reliableanchoring for a pre-formed deformable intrafallopian device. Theintrafallopian device of the present invention therefore comprises aresilient structure, usually a metallic coil, which includes a copperalloy, a copper plating, or copper fibers, ideally comprising an alloyincluding at least 75% copper. The coil material typically includesberyllium, zinc, stainless steel, platinum, a shape memory alloy such asNitinol™, or the like. Preferably, the coil is composed of an alloy ofberyllium and copper. Although the present device will generally resultin occlusion, it need not completely occlude the fallopian tube toprevent the meeting of the sperm and ovum. Instead, the presence of thecopper on the resilient structure is sufficient to provide effectivecontraception.

[0020] Conveniently, the present invention further comprisesnon-surgical placement of such intrafallopian devices by transcervicalintroduction. The resilient structure is restrainable in a straightconfiguration, e.g., by inserting the device within a catheter, greatlyfacilitating and reducing the risks of introduction. Thus, the cost anddangers associated with existing surgical contraceptive andsterilization procedures are avoided.

[0021] In a first aspect, a contraceptive intrafallopian deviceaccording to the present invention comprises a resilient structurehaving a proximal end and a distal end. The resilient structurecomprises copper, and is biased to form at least one bend near theproximal end of the primary coil. Similarly, the resilient structure isalso biased to form at least one bend near its distal end. Theseproximal and distal bends define an isthmus-traversing regiontherebetween. Preferably, the isthmus-traversing region also includes atleast one bend, thereby helping to anchor the coil within the fallopiantube.

[0022] Generally, the resilient structure of the present intrafallopiandevice will be formed as a primary coil. To help restrain the coilwithin the fallopian tube, fibers are attached to some embodiments ofthe coil, the fibers optionally comprising a polyester material such asRayon™, Dacron™, or the like. Alternatively, copper fibers may be usedto increase the exposed copper surface area, the copper fibers generallyhaving a diameter on the order of 0.001 inches.

[0023] The bends of the present intrafallopian device are generallyformed as a secondary shape imposed on a primary coil. The primary coilis most easily formed as a straight cylindrical coil. The secondaryshape will be imposed on the primary coil by bending, optionally heattreating the primary coil while bent. The individual bends may take awide variety of forms, including sinusoidal curves, the individual loopsof a continuous secondary coil, or the like. However, the secondaryshape generally defines an overall width which is larger than thefallopian tube, so that the tubal wall restrains the resilient structurewhen it is released.

[0024] Preferably, each of the bends of the present intrafallopiandevice forms a loop in the primary coil when in a relaxed state.Ideally, the loops are separated by straight sections of coil. Thealternating of loops with straight sections of coil forms a largediameter “flower coil,” which provides a large relaxed overall width,and also features bends of tight radius, both of which promoteretention. Conveniently, the primary coil generally has a diameter lessthan that of the fallopian tube, and can be restrained in a straightconfiguration for placement within the fallopian tube, typically byinserting the primary coil within a delivery catheter.

[0025] In another aspect, a contraceptive intrafallopian deviceaccording to the present invention comprises a resilient primary coilhaving a primary coil diameter. The primary coil comprises copper, andforms a secondary shape when in a relaxed state. The secondary shapedefines a plurality of bends and an overall width which is larger thanthe primary coil diameter. Thus the primary coil can be easily anchoredin a fallopian tube which is smaller in diameter than the secondaryshape. Preferably, the present device reacts with a force sufficient toprevent axial movement of the device within the fallopian tube whenrestrained in a lumen having a diameter in the range between 0.5 mm and3 mm. The actual anchoring force will depend on the shape of the coiland the modulus of elasticity of the material used.

[0026] In yet another aspect, a intrafallopian contraceptive deliverysystem according to the present invention comprises an elongate body inwhich the resilient primary coil described above is slidably disposed. Ashaft is also slidably disposed within the elongate body and is locatedproximally of the primary coil. The distal end of the shaft includes acoil interface surface, while the elongate body restrains the primarycoil in a straight configuration.

[0027] Preferably, a bend in the isthmus-traversing region of thepresent intrafallopian device, together with the proximal and distalanchor bends, restrains the resilient structure within the isthmus ofthe fallopian tube. The distal anchor is inserted into the ampulla,distal of the isthmus, while the proximal anchor is located in theostium, proximal of the isthmus. Unintended movement of the device isfurther avoided by locating the isthmus-traversing region within theisthmus to resiliently impose anchoring forces against the tubal wall.

[0028] In a still further aspect, an intrafallopian contraceptive methodaccording to the principles of the present invention comprisesrestraining a resilient structure in a straight configuration andtranscervically inserting the resilient structure into a fallopian tube.The resilient structure is affixed within the isthmus by releasing abent isthmus-traversing region. The bend of the isthmus-traversingregion exerts a force against the wall of the fallopian tube, anchoringthe device within the isthmus. Preferably, a distal anchor on theresilient structure is released distally of the isthmus, and a proximalanchor is released proximally of the isthmus, the distal and proximalanchors generally formed from bends in the resilient structure.Optionally, an electric current is applied through the resilientstructure to the fallopian tube, thereby effecting permanentsterilization.

BRIEF DESCRIPTION OF THE DRAWINGS

[0029]FIG. 1 illustrates a first embodiment of a contraceptiveintrafallopian device according to the present invention having a singledistal anchor loop, a single proximal anchor loop, and anisthmus-traversing region having a single loop for anchoring the devicewithin the fallopian tube.

[0030]FIG. 2 illustrates an alternative embodiment of a contraceptiveintrafallopian device according to the present invention having aplurality of loops which may act as proximal, distal, or lumen anchors.

[0031]FIG. 3 illustrates the distal portion of a delivery catheter forplacement of a contraceptive intrafallopian device according to thepresent invention.

[0032]FIG. 4 illustrates the contraceptive intrafallopian device of FIG.1 partially released from the delivery catheter of FIG. 3.

[0033]FIGS. 5 and 6 illustrate a contraceptive method using anintrafallopian device according to the principles of the presentinvention.

DESCRIPTION OF THE SPECIFIC EMBODIMENTS

[0034] The present invention encompasses a contraceptive intrafallopiandevice which can alternatively be used as both a permanent and areversible means of contraception. The present contraceptive methods anddevices minimize the danger of non-use which has limited the efficacy ofprior art contraceptive techniques. Moreover, the location of thepresent devices within the fallopian tubes provides a reduced risk ofthe infectious complications, increased bleeding, and pelvic painassociated with intrauterine devices (IUDs). Furthermore, the locationand the novel shape of the present intrafallopian device providessignificant advantages over IUDs, which have been found to besusceptible to unplanned expulsion and removal due to excessive pain andbleeding. The present invention takes advantage of the increase ineffectiveness associated with copper IUDs, providing a resilientstructure including copper which may be transcervically positionedwithout the need for surgery.

[0035] Although the present contraceptive method may be included withina group of contraceptive techniques generally referred to as fallopiantube occlusion methods, the present invention does not necessarily relysolely on blocking the fallopian tube to prevent fertilization. Instead,contraception is apparently provided by disrupting of ovum transport,the process of fertilization, and/or cleavage of the ovum. While theeffect that copper has on these processes is not fully understood, itdoes appear that copper intrafallopian devices offer potentiallysignificant increases in effectiveness over intrafallopian devicesformed of other materials. Optionally, the present invention furtherencompasses devices which promote tissue growth within the tube toinduce tubal occlusion, further inhibiting conception.

[0036] The present invention is anchored within the isthmus of thefallopian tube, overcoming the unintended expulsion of the device andthe resulting failure of the contraceptive method. Such intrafallopiandevice expulsion has been the single greatest factor limiting theefficacy of easily positioned intrafallopian contraceptive techniques.

[0037] The present intrafallopian devices are generally elongateresilient structures pre-formed into secondary shapes. These secondaryshapes will bias the resilient structure so as to provide strong forcesagainst the lumen wall of the fallopian tube. Clearly, the secondaryshape must have a larger outer diameter than the inner diameter of thefallopian tube.

[0038] Conveniently, the present resilient structures are insertableinto a catheter, the catheter wall restraining the resilient structurein a straight configuration. As the resilient structure has an outerdiameter when in the straight configuration which is less than the innerdiameter of the fallopian tube, the catheter containing the presentintrafallopian device is easily transcervically introduced. Moreover,the device is readily removed by snaring the resilient structure nearthe proximal end and pulling proximally on the resilient structure,thereby straightening the resilient structure and allowing it to bewithdrawn without injuring the fallopian tube. Alternatively, anelectrical current is applied to the device after it is at leastpartially releasing the fallopian tube, providing permanentsterilization.

[0039] Referring now to FIG. 1, a first embodiment of the presentcontraceptive intrafallopian device 10 is formed from a resilientprimary coil 12. Primary coil 12 is most easily originally formed as astraight cylindrical coil or spring, preferably having an outer diameterin the range from 0.2 mm to 5 mm, and having a length in the range from20 mm to 150 mm. Ideally, primary coil 12 has an outer diameter in therange from 0.4 mm to 2 mm and a length in the range from 30 mm to 70 mm.The straight primary coil may then be bent into a variety of secondaryshapes.

[0040] The primary coil 12 of intrafallopian device 10 includes aproximal end 14 and a distal end 16. Between these ends, three loops 20are formed, each having an inner diameter 22. Located between loops 20are straight sections 24, which increase the overall cross-section ofthe intrafallopian device to an overall width 26. Preferably, innerdiameter 22 is in the range from 2 mm to 10 mm, while overall width 26is at least 6 mm, ideally being in the range from 8 mm to 40 mm. Distaland proximal ends 14, 16 each include an atraumatic endcap 18 to preventinjury to the fallopian tube.

[0041] Preferably, primary coil 12 is formed from a beryllium copperalloy wire. Beryllium copper provides the resilience necessary to avoidexpulsion of the device, and also provides the increased effectivenessof a copper contraceptive intrafallopian device. Alternatively, primarycoil 12 is formed from a resilient metal, such as stainless steel,platinum, a shape memory alloy, or the like. If such materials are used,primary coil 12 is preferably plated with copper or a copper alloy orotherwise has copper attached.

[0042] To further reduce the possibility of expulsion of intrafallopiandevice 10, fibers are optionally carried on primary coil 12. The fibersmay be short individual fibers, or may alternatively be wound intoprimary coil 12. Preferably, the fibers comprise copper, therebyincreasing the total copper surface area. Such copper fibers arepreferably bonded to primary coil 12 with solder, brazing, a polymericadhesive, or the like. Alternatively, polyester fibers such as Dacron™,Rayon™, or the like, are bonded to the surface of primary coil 12 usinga polymeric adhesive. The polyester fibers promote increased tissuegrowth around the coil, thus further reducing the possibility ofexpulsion of the device from the fallopian tube.

[0043] A secondary shape has been superimposed on the primary coil toform intrafallopian device 10, the secondary shape comprising loops 20separated by straight sections 24. This secondary shape is hereinreferred to as a “flower coil.” The flower coil shape is particularlyadvantageous in that outer diameter 26 is substantially larger than theprimary coil diameter, while the individual loops 20 have relativelysmall inner diameters 22 which will maintain the largest possibleanchoring force against the fallopian tube. Minimizing inner diameter 22also ensures that anchoring force is applied within the fallopian tube,despite the curvature of the fallopian tube.

[0044] Referring now to FIG. 2, an alternative embodiment of the presentcontraceptive intrafallopian device 30 includes additional loops toensure anchoring of the device within the fallopian tube. Alternativeembodiment 30 is formed from an elongate primary coil 32 having aproximal end 34 and a distal end (not shown). Elongate primary coil 32has an outer diameter 36 which is smaller than the isthmus of thefallopian tube, allowing the straightened intrafallopian device to beinserted easily. Elongate primary coil 32 has been bent to form asecondary shape including a larger number of loops 38 than theembodiment of FIG. 1. Loops 38 have an outer diameter 40 which is largerthan the inner diameter of the fallopian tube, preventing loops 38 fromassuming their relaxed shape. Loops 38 are again separated by straightsections 42 of elongate primary coil 32, increasing the overallintrafallopian device diameter 44.

[0045] In both embodiments of the present intrafallopian device 10, 30,at least one loop adjacent to the proximal end is disposed proximally ofthe narrowest portion of the fallopian tube, referred to as the isthmus.Similarly, at least one loop of the intrafallopian device is disposeddistally of the isthmus. These proximal and distal loops act as anchors,helping to prevent proximal or distal movement of the intrafallopiandevice. In the embodiment of FIG. 2, at least one loop is also disposedadjacent to the isthmus of the fallopian tube, further helping toprevent unintentional expulsion.

[0046] Alternative intrafallopian device 30 may be positioned withmultiple loops acting as proximal or distal anchors, or mayalternatively have all but the proximal and distal anchor loops disposedalong the fallopian tube to act as anchors within the lumen of thatbody. Advantageously, the embodiment of FIG. 2 is therefore lesssensitive to variations in total fallopian tube length.

[0047] Referring now to FIG. 3, a delivery catheter for the presentintrafallopian device comprises an elongate body 52 and a shaft 54.Elongate body 52 includes a lumen 56 in which shaft 54 is disposed,shaft 54 being slidable in the axial direction. Shaft 54 includes a core58 having a tapered distal end 60, allowing the device to navigatethrough tortuous bends while retaining the column strength required toadvance the device. Core 58 extends proximally through elongate body 52,and is capable of transferring compressive forces through the elongatebody. Core 58 is typically formed from stainless steel, a stainlessalloy, or the like. Disposed over distal end 60 of core 58 is pusher cap62. Pusher cap 62 provides a low friction, deformable end piece having adistal coil interface surface 64. Pusher cap 62 is preferably formed ofa low friction polymer such as PTFE, or the like.

[0048] Intrafallopian delivery catheter 50 receives the presentintrafallopian device within the distal end of lumen 56 of elongate body52. Lumen 56 has an inner diameter which is slightly larger than outerdiameter 36 of the primary coil. The present intrafallopian device istherefore straightened to a straight configuration as it is loadedproximally into the distal end of lumen 56. Elongate body 52 issufficiently strong to restrain the primary coil in the straightconfiguration, but must remain sufficiently flexible to allowmaneuvering within the body lumen. Elongate body 52 is preferably formedfrom an inelastic, flexible material such as polyurethane, PET, or thelike.

[0049] Referring now to FIG. 4, intrafallopian device 10 is releasedfrom delivery catheter 50 within the fallopian tube by holding shaft 54while proximally withdrawing elongate body 52. Distal coil interfacesurface 64 engages the proximal end 14 of primary coil 12. Initially,primary coil 12 is restrained in a straight configuration by elongatebody 52. As elongate body 52 is withdrawn, primary coil 12 is released.When primary coil 12 is unrestrained it forms loop 20; when releasedwithin the fallopian tube it will generally be restrained by the tubalwall in a configuration between straight and the relaxed secondaryshape. Preferably, the first loop released will form a distal anchorbend 66. Subsequent loops will bias primary coil 12 against thefallopian tube, and form a proximal anchor bend, in that order.

[0050] Use of the present contraceptive intrafallopian device will bedescribed with reference to FIGS. 5 and 6. A uterine introducer cannula70 is inserted transcervically through a uterus 72 to the region of anostium 74. Elongate body 52 is then extended distally from cannula 70into a fallopian tube 77, preferably guided under fluoroscopy.Alternatively, a hysteroscope may be used in place of cannula 70.Elongate body 52 is maneuvered using a guide wire 78 past an isthmus 80.

[0051] After elongate body 52 extends past isthmus 80, guide wire 78 isremoved. An intrafallopian device according to the present invention isinserted in the proximal end of elongate body 52, the intrafallopiandevice being restrained in a straight configuration by the elongatebody. The device is advanced distally using shaft 54, the shaft andelongate body forming delivery catheter 50 (FIG. 3). Delivery catheter50 is axially positioned so that at least one loop of the intrafallopiandevice is within a target region 84 adjacent to isthmus 80. Preferably,at least one loop is distal of target region 84, and at least one loopis proximal of target region 84 to form the distal and proximal anchorbends of the implanted intrafallopian device.

[0052] Once delivery catheter 50 is properly positioned, elongate body52 may be axially withdrawn. Shaft 54 axially restrains theintrafallopian device at the target location during withdrawal ofelongate body 52, as described regarding FIG. 4. As the distal end ofthe primary coil is released, the distal loop forms a distal anchor bend90. Similarly, the proximal loop forms a proximal anchor bend 92.Intermediate loops are restrained within the narrow target region 84,exerting substantial anchoring forces against the walls of the fallopiantube. As seen in FIG. 6, the loops need not assume their relaxed form toprovide effective distal or proximal anchors.

[0053] The present invention further encompasses permanent sterilizationby passing a current through the shaft to the intrafallopian deviceafter elongate body 52 has been partially withdrawn, but before theintrafallopian device is fully released. Fallopian tube tissue incontact with the intrafallopian device is desiccated, and thus attachedto the present intrafallopian device. This action also causes permanenttubal damage, leading to the formation of scar tissue which encapsulatesthe intrafallopian device and causes permanent occlusion of the tuballumen. Clearly, the resilient member/shaft interface must be conductiveto allow the present non-surgical method of permanent sterilization.

[0054] In conclusion, the present invention provides a contraceptiveintrafallopian device which may be positioned without surgery. While theabove is a complete description of the preferred embodiments of theinvention, various alternatives, modifications, and equivalents may beused. For example, a wide variety of secondary shapes, including openloops, continuous bends, sinusoidal curves, or the like, may be imposedon the primary coil. Therefore, the above description should not betaken as limiting the scope of the invention, which is defined insteadsolely by the appended claims.

What is claimed is:
 1. A contraceptive delivery system comprising: anelongate body having a proximal end, a distal end, and a delivery lumen,the distal end configured for advancement into an ostium of a fallopiantube; a shaft slidably disposed within the delivery lumen of theelongate body; and a resilient contraceptive device loadable within thedelivery lumen of the distal end of the elongate body, the contraceptivedevice biased to anchor the contraceptive device within the fallopiantube upon release from the delivery lumen by retraction of the elongatebody relative to the shaft; and fibers disposed along the contraceptivedevice, the fibers configured to assist in anchoring the contraceptivedevice within the fallopian tube.
 2. A system as in claim 1, wherein thecontraceptive device comprises a coil having a proximal end and distalend and biased to form at least one bend therebetween, the at least onebend comprising at least one proximal anchor bend near the proximal endof the coil and at least one distal anchor bend near the distal end ofthe coil.
 3. A system as in claim 2, wherein the coil includes anisthmus-traversing region between the at least one proximal anchor bendand the at least one distal anchor bend, the length of theisthmus-traversing region sized to traverse an isthmus within thefallopian tube.
 4. A system as in claim 3, wherein theisthmus-traversing region includes a bend to assist in anchoring withinthe isthmus.
 5. A system as in claim 1, wherein the fibers comprise apolyester material.
 6. A system as in claim 1, wherein the fiberscomprise copper.
 7. A system as in claim 6, wherein each fiber has adiameter of approximately 0.001 inches.
 8. A system as in claim 1,wherein the contraceptive device comprises beryllium, zinc, stainlesssteel, platinum, or a shape memory alloy.
 9. A system as in claim 1,wherein the shaft includes a core having a tapered distal end, the coreconfigured to retain column strength during advancement of the elongatebody into the ostium of the fallopian tube.
 10. A system as in claim 9,wherein the core comprises stainless steel or a stainless alloy.
 11. Asystem as in claim 9, wherein the shaft includes a pusher cap over thedistal end of the core, the pusher cap including a distal contraceptivedevice interface surface configured to engage the contraceptive deviceto maintain position of the contraceptive device during retraction ofthe elongate body.
 12. A system as in claim 11, wherein the pusher capcomprises a low friction polymer.
 13. An intrafallopian contraceptivemethod comprising; providing contraceptive delivery system comprising anelongate body having a proximal end, a distal end, and a delivery lumen,and a shaft slidably disposed within the delivery lumen of the elongatebody, and a resilient contraceptive device loaded within the deliverylumen of the distal end of the elongate body, the contraceptive devicebiased to anchor the contraceptive device within a fallopian tube uponrelease from the delivery lumen, and fibers disposed along thecontraceptive device, the fibers configured to assist in anchoring thecoil within the fallopian tube; inserting the distal end of the elongatebody within an ostium of the fallopian tube; and retracting the elongatebody relative to the shaft, wherein such retraction releases thecontraceptive device allowing anchoring of the contraceptive devicewithin the fallopian tube.
 14. A method as in claim 13, wherein thecontraceptive device comprises a coil including a proximal end and adistal end and biased to form at least one bend therebetween, the atleast one bend comprising at least one proximal anchor bend near theproximal end of the coil and at least one distal anchor near the distalend of the coil, and wherein retracting includes releasing the at leastone distal anchor bend at a first location within the fallopian tube andthen releasing the at least one proximal anchor bend at a secondlocation proximal to the first location.
 15. A method as in claim 14,wherein the first location includes an ampulla of the fallopian tube andthe second location includes the ostium of the fallopian tube.
 16. Amethod as in claim 15, wherein the coil includes an isthmus-traversingregion between the at least one proximal anchor bend and the at leastone distal anchor bend, the isthmus-traversing region including a bend,and wherein retracting includes releasing the isthmus-traversing regionwithin as isthmus between the ampulla and ostium so that the bendassists in anchoring within the isthmus.
 17. The method of claim 13,further comprising loading the resilient contraceptive device within thedelivery lumen of the distal end of the elongate body.
 18. The method ofclaim 13, further comprising maintaining position of the shaft relativeto the fallopian tube during retraction of the elongate body.
 19. Themethod of claim 13, further comprising removing the elongate body andshaft from the fallopian tube and leaving the contraceptive deviceanchored within the fallopian tube.